Islamic State launched separate attacks on Iraq’s capital Sunday, including the largest in two years on the city’s outskirts and a bombing that killed at least 34 people, officials said. The attacks show how Islamic State continues to pose a formidable threat to Iraq’s political and security center even after recent losses in other regions. The assault on the town of Abu Ghraib marked the largest-scale attack there since the militancy swept through Iraq in 2014. Meanwhile, the marketplace bombing, in the heart of…